Start with the headset turned off. Then, press and hold the Multifunction control for 8 seconds, until the blue and red lights flash alternately. It is now in pairing mode. Now, make your phone's bluetooth application search for new devices. After a while, 'CV-M225' will appear in the phone' screen. Select it and command the application to proceed. If a pairing code (or PIN, or passkey) is requested, enter '1234'. If pairing is successful, the headset will enter the stand-by mode.
By the way, in case your headset's user guide happens to be missing, feel free to download it from
this location.
Hope it works for you.
Cheers!
Carlos